Mine is center back. I love myself!

Most new sinks have them towards the back. Most older in the middle. This makes a retrofit a pain because some newer sinks are 8-10 inches deep. The drain lines often need to be reworked by a plumber $$$

Mikespringer: where do you recommend the drain hole to be? Also, all the depths are so confusing, what is the ideal depth?

The term is "offset drain" (i.e. not in the center), and it offers a couple of advantages. It allows you to set down, e.g., a roasting pan to soak, without covering the drain hole. Also, it allows more room under the sink for storage, trash, whatever, because your plumbing and disposal are not smack-dab in the center.

I don't quite agree with Mikespringer. Typically what causes the plumbing to need to be retrofit from an older sink is the depth of the new sink (plus countertop which adds about an inch). Older sinks might be 6 or 7 inches deep, and as Mike said, newer sinks tend to be 8-9+" deep plus a thicker countertop than, say, formica was. Also, newer disposals tend to be bigger than the older ones. That means your older plumbing outlet position out of the wall could be too high. But moving the sink's drain hole 2-3 inches from the center of the sink to the back isn't as disruptive. I had an older shallow sink with a center drain that I replaced with a 9" deep sink with an offset drain in the rear right. Luckily, my plumbing didn't need any changes, even with the added depth of the sink, thicker countertop and big disposal. It just depends on your setup.

I really like my sink's offset drain hole in the rear right. But it is more common to find sinks' offset drains in the rear center which is fine too. So I wouldn't worry if the drain is offset center or offset right; just having it offset is an advantage. There's only a few sinks I know of that are offset to the right, which are the Blancodiamond Supersingle in Silgranit (very large sink), the Elkay Elumina, some of the Shaws fireclay sinks and the Rachiele sinks. But you can easily find quite a number of sinks at all price points with an offset drain rear center.

I think 'bottom' is a good location. Beyond that, I have no real preference.

My Blanco Precis super single sink drain is center back. Works fine for me.

The placement of the faucet relative to the drain is not too much of a concern, assuming your faucet or pull-out will allow you to swivel/wherever you need. The drain cannot be moved though, so that is a bigger deal for convenience and ergonomics!

Professional chefs reccommend a rear-left drain placement. Why? Most people are right handed, and will use the sprayer with their right hand. This allows the user to ergonomically direct the spray to rinse the sink toward the left with the most ease. The corner is the most effiient, because you can direct dirt and debris to the corner, and get it down the drain with speed using the two corner walls of the sink to assist. A center drain placement (away from the sink walls) is the worst, because it results in repeated circling motions while "chasing" debris over, and over. (The proverbial expresion, "circling the drain" referring to something that is close, but never completed, encapsulates this well known irritation perfectly!) Obviously, if you use your sink regularly and are left handed, you should reverse this and use a rear-right position instead!

Technically the drain takes the same amount of space regardless of where it is located, but putting it in the corner allows for the least intrusion into the body of the sink, and doesn't cut the working area in half by centering it (front to back, or right to left). Corner placement also allows you to place a large item in the sink, without blocking the drain, or wash items without a collander without them falling down the drain.

Rear corner corner (either side) placement allows more efficient use of space under the sink, because the drain and disposal will interfere with that space less.

While a faucet can swivel or be pulled out to wherever, the drain cannot be moved, so it is important for convenience and ergonomics!

Professional chefs reccommend a rear-left drain placement. Why? Most people are right handed, and will use the sprayer with their right hand. This allows the user to ergonomically direct the spray to rinse the sink toward the left with the most ease. The corner is the most effiient, because you can direct dirt and debris to the corner, and get it down the drain with speed using the two corner walls of the sink to assist. A center drain placement (away from the sink walls) is the worst, because it results in repeated circling motions while "chasing" debris over, and over. (The proverbial expresion, "circling the drain" referring to something that is close, but never completed, encapsulates this well known irritation perfectly!) Obviously, if you use your sink regularly and are left handed, you should reverse this and use a rear-right position instead!

Technically the drain takes the same amount of space regardless of where it is located, but putting it in the corner allows for the least intrusion into the body of the sink, and doesn't cut the working area in half by centering it (front to back, or right to left). Corner placement also allows you to place a large item in the sink, without blocking the drain, or wash items without a collander without them falling down the drain.

Rear corner placement (either side) allows more efficient use of space under the sink as well, because the drain and disposal will interfere with that space less.

The rear corner is the best position, with the rear-left being slightly advantageous. Either rear corner will be a great benefit overall.

The exception to the rear corner rule, is really for very long sinks. When a sink exceeds 36", and you are not in a commercial setting where the pans are very large, you essentially have two work spaces in your sink. Very occasionally, especially with a very long narrow sink, it may be an advantage to have a drain in the center back. Consider how you cook carefully. You will have only one sink wall to assist with rinsing, and you may wind up just chasing the debris from side to side while trying to get it down the drain.

One argument you will hear against placing the drain against the wall of the sink is splashback. This is a complicated fluidics issue created by the curvature (or lack of curvature) of the lower edges of the sink, the height and pressure of your faucet, and the drain position. You cannot blame this on the drain position alone. Buying a deep sink, installing a faucet that isn't too high, and not turning your faucet on full-blast is the easiest way to reduce splashback. (If it bothers you at all.)

After we have trained the sink companies to make ergonomic sinks, we can begin getting the foot and knee-operated faucets! (They don't fail like the electric sensor faucets).

“foot-operated faucets!”

I would really like a foot operated faucet, to save water when handwashing and to confuse kitchen interlopers.

What is a good way to add foot operation to an existing faucet?

Center drain is usually the most popular option. A left or a right offset drain gives you more usable space under the cabinet. Especially if you install a garbage disposal. If you go with an offset drain sink, especially if it's a 30" or larger sink, try to get one with a true slope bottom. Many of the large rectangular sinks nowadays have a very flat bottom, and an offset drain will make it extremely hard to clean the sink every day and push all the food particles towards the drain that is on one corner or side.